Ludite though I may be, I have gone to poly-pro as a base layer. I've yet to move on to gore-tex for my outter layer but the day of reckoning for my ancient 60/40 parka is approaching ever faster - and the British waxed cotton stuff just seems so danged stiff. Wool sweaters, wool pants, wool socks - how can you argue with centuries of refinement and use?
If your stuff is still in great condition - use it - the theory is the same - it's just the materials that have changed. I will say that wool never gets to stinking the way poly-pro does - at least not when reacting to my body -